package com.mg.utils;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.Random;

/**
 * @author mg1213
 * 2018/3/28
 **/
public class VerifyCodeUtils {


    //使用到Algerian字体，系统里没有的话需要安装字体，字体只显示大写，去掉了1,0,i,o几个容易混淆的字符

    public static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";

    private static Random random = new Random();


    /**
     * 使用系统默认字符源生成验证码
     *
     * @param verifySize 验证码长度
     * @return
     */

    public static String generateVerifyCode(int verifySize) {

        return generateVerifyCode(verifySize, VERIFY_CODES);

    }

    /**
     * 使用指定源生成验证码
     *
     * @param verifySize 验证码长度
     * @param sources    验证码字符源
     * @return
     */

    public static String generateVerifyCode(int verifySize, String sources) {

        if (sources == null || sources.length() == 0) {

            sources = VERIFY_CODES;

        }

        int codesLen = sources.length();

        Random rand = new Random(System.currentTimeMillis());

        StringBuilder verifyCode = new StringBuilder(verifySize);

        for (int i = 0; i < verifySize; i++) {

            verifyCode.append(sources.charAt(rand.nextInt(codesLen - 1)));

        }

        return verifyCode.toString();

    }


    /**
     * 生成随机验证码文件,并返回验证码值
     *
     * @param w
     * @param h
     * @param outputFile
     * @param verifySize
     * @return
     * @throws IOException
     */

    public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException {

        String verifyCode = generateVerifyCode(verifySize);

        outputImage(w, h, outputFile, verifyCode);

        return verifyCode;

    }


    /**
     * 输出随机验证码图片流,并返回验证码值
     *
     * @param w
     * @param h
     * @param os
     * @param verifySize
     * @return
     * @throws IOException
     */

    public static String outputVerifyImage(int w, int h, OutputStream os, int verifySize) throws IOException {

        String verifyCode = generateVerifyCode(verifySize);

        outputImage(w, h, os, verifyCode);

        return verifyCode;

    }


    /**
     * 生成指定验证码图像文件
     *
     * @param w
     * @param h
     * @param outputFile
     * @param code
     * @throws IOException
     */

    public static void outputImage(int w, int h, File outputFile, String code) throws IOException {

        if (outputFile == null) {

            return;

        }

        File dir = outputFile.getParentFile();

        if (!dir.exists()) {

            dir.mkdirs();

        }

        try {

            outputFile.createNewFile();

            FileOutputStream fos = new FileOutputStream(outputFile);

            outputImage(w, h, fos, code);

            fos.close();

        } catch (IOException e) {

            throw e;

        }

    }


    /**
     * 输出指定验证码图片流
     *
     * @param w
     * @param h
     * @param os
     * @param code
     * @throws IOException
     */

    public static void outputImage(int w, int h, OutputStream os, String code) throws IOException {

        int verifySize = code.length();

        BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);

        Random rand = new Random();

        Graphics2D g2 = image.createGraphics();

        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

        Color[] colors = new Color[5];

        Color[] colorSpaces = new Color[]{Color.WHITE, Color.CYAN,

                Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,

                Color.PINK, Color.YELLOW};

        float[] fractions = new float[colors.length];

        for (int i = 0; i < colors.length; i++) {

            colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];

            fractions[i] = rand.nextFloat();

        }

        Arrays.sort(fractions);


        g2.setColor(Color.GRAY);// 设置边框色

        g2.fillRect(0, 0, w, h);


        Color c = getRandColor(200, 250);

        g2.setColor(c);// 设置背景色

        g2.fillRect(0, 2, w, h - 4);


        //绘制干扰线

        Random random = new Random();

        g2.setColor(getRandColor(160, 200));// 设置线条的颜色

        for (int i = 0; i < 20; i++) {

            int x = random.nextInt(w - 1);

            int y = random.nextInt(h - 1);

            int xl = random.nextInt(6) + 1;

            int yl = random.nextInt(12) + 1;

            g2.drawLine(x, y, x + xl + 40, y + yl + 20);

        }


        // 添加噪点

        float yawpRate = 0.05f;// 噪声率

        int area = (int) (yawpRate * w * h);

        for (int i = 0; i < area; i++) {

            int x = random.nextInt(w);

            int y = random.nextInt(h);

            int rgb = getRandomIntColor();

            image.setRGB(x, y, rgb);

        }


        shear(g2, w, h, c);// 使图片扭曲


        g2.setColor(getRandColor(100, 160));

        int fontSize = h - 4;

        Font font = new Font("Algerian", Font.ITALIC, fontSize);

        g2.setFont(font);

        char[] chars = code.toCharArray();

        for (int i = 0; i < verifySize; i++) {

            AffineTransform affine = new AffineTransform();

            affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize / 2, h / 2);

            g2.setTransform(affine);

            g2.drawChars(chars, i, 1, ((w - 10) / verifySize) * i + 5, h / 2 + fontSize / 2 - 10);

        }


        g2.dispose();

        ImageIO.write(image, "jpg", os);

    }


    private static Color getRandColor(int fc, int bc) {

        if (fc > 255)

            fc = 255;

        if (bc > 255)

            bc = 255;

        int r = fc + random.nextInt(bc - fc);

        int g = fc + random.nextInt(bc - fc);

        int b = fc + random.nextInt(bc - fc);

        return new Color(r, g, b);

    }


    private static int getRandomIntColor() {

        int[] rgb = getRandomRgb();

        int color = 0;

        for (int c : rgb) {

            color = color << 8;

            color = color | c;

        }

        return color;

    }


    private static int[] getRandomRgb() {

        int[] rgb = new int[3];

        for (int i = 0; i < 3; i++) {

            rgb[i] = random.nextInt(255);

        }

        return rgb;

    }


    private static void shear(Graphics g, int w1, int h1, Color color) {

        shearX(g, w1, h1, color);

        shearY(g, w1, h1, color);

    }


    private static void shearX(Graphics g, int w1, int h1, Color color) {


        int period = random.nextInt(2);


        boolean borderGap = true;

        int frames = 1;

        int phase = random.nextInt(2);


        for (int i = 0; i < h1; i++) {

            double d = (double) (period >> 1)

                    * Math.sin((double) i / (double) period

                    + (6.2831853071795862D * (double) phase)

                    / (double) frames);

            g.copyArea(0, i, w1, 1, (int) d, 0);

            if (borderGap) {

                g.setColor(color);

                g.drawLine((int) d, i, 0, i);

                g.drawLine((int) d + w1, i, w1, i);

            }

        }


    }


    private static void shearY(Graphics g, int w1, int h1, Color color) {


        int period = random.nextInt(40) + 10; // 50;


        boolean borderGap = true;

        int frames = 20;

        int phase = 7;

        for (int i = 0; i < w1; i++) {

            double d = (double) (period >> 1)

                    * Math.sin((double) i / (double) period

                    + (6.2831853071795862D * (double) phase)

                    / (double) frames);

            g.copyArea(i, 0, 1, h1, 0, (int) d);

            if (borderGap) {

                g.setColor(color);

                g.drawLine(i, (int) d, i, 0);

                g.drawLine(i, (int) d + h1, i, h1);

            }


        }


    }

    public static void main(String[] args) throws IOException {

        File dir = new File("F:/verifies");

        int w = 200, h = 80;

        for (int i = 0; i < 50; i++) {

            String verifyCode = generateVerifyCode(4);

            File file = new File(dir, verifyCode + ".jpg");

            outputImage(w, h, file, verifyCode);

        }

    }

}
